There’s only been one president who was an actual movie star — Ronald Reagan, of course. But Reagan wasn’t the one movie-star president. That would be John F. Kennedy. JFK had the looks, the glamour, the manner of a screen idol. Even Reagan, as he often cheerfully conceded, never reached the upper strata of the Hollywood firmament. With JFK, there was always the sense he could have. There’s a famous apocryphal story about studio chief Jack Warner’s response when he first heard Reagan was running for office. “No, no, Jimmy Stewart for governor — Ronnie Reagan for best friend.” No one ever thought to cast JFK as best friend — or even governor. He went straight to the celestial top.

In some ways, Kennedy’s movie-star status seems even more secure today, nearly 50 years after his assassination, than it did when he was in the White House. The star power he showed then seems that much more potent now, enlarged by time’s passage, romanticized by an early death, heightened by all that we’ve come to learn about what might euphemistically be called his leading-man lifestyle. Looking like a movie star, as JFK did, is one thing. Living like a movie star, as he also did, is quite another. He even had a movie-star wife. Jacqueline Kennedy was Audrey Hepburn with a breathy voice and equally classy accent.

Kennedy’s associations with the movies extend beyond style and persona. They include family and personal connections and films made about him. Usually when people talk about Kennedy as the first media president, they’re thinking of television. They forget that the movies are a medium, too, and they did so much to shape Kennedy.

Reagan came to the movies indirectly, by way of a radio broadcast booth. For JFK, they were a birthright. His father, Joseph P. Kennedy Sr., had run a small studio, FBO, and played a role in assembling one of the most important studios of Hollywood’s Golden Age, RKO.

During his Hollywood period, the elder Kennedy famously dallied with Gloria Swanson. Hollywood associations, romantic and otherwise, added to his son’s luster. Frank Sinatra was such a friend that JFK was practically an honorary member of the Rat Pack — certainly, he subscribed to its ring-a-ding-ding ethos — and his movie-star brother-in-law, Peter Lawford, was a member in full standing.

In his diaries, the theater critic Kenneth Tynan recorded Marlene Dietrich’s description of a visit to the Kennedy White House. The president wondered if his father had ever been intimate with her. No, Dietrich told him. His curiosity satisfied, JFK then achieved the intimacy his father had not.

As a young man, Kennedy had dated the movie star Gene Tierney. Later there would be all those rumors about his sleeping with Marilyn Monroe. Did he or didn’t he? It hardly matters. The famous film of her singing “Happy Birthday” to him at Madison Square Garden, in 1962, has a voltage that goes beyond sex. “I can now retire from politics,” Kennedy quipped to the crowd, “after having had ‘Happy Birthday’ sung to me in such a sweet, wholesome way.” George Clooney couldn’t have handled it with better cocked-eyebrow aplomb. Of course, like so many others, Clooney had Kennedy to follow as a public model of male conduct.

Perhaps the clearest indicator of JFK’s star power has been his popularity with filmmakers. He’s been portrayed scores of times in movies and on television. In recent months, he’s shown up in “The Butler” (played by James Marsden) and “Parkland.” Brett Stimely, the actor who plays him in “Parkland,” has appeared as Kennedy no fewer than four times — perhaps most memorably in “Watchmen” (2009), shaking hands with blue-skinned Dr. Manhattan on the South Lawn of the White House.

CECIL STOUGHTON/ASSOCIATED PRESS/FILE 1962

Marilyn Monroe with Robert and John Kennedy.

The most recent portrayal comes this Sunday night, with Rob Lowe playing JFK in the television adaptation of Bill O’Reilly and Martin Dugard’s bestseller, “Killing Kennedy.” Lowe isn’t an actor one necessarily thinks of in terms of Kennedy. But he meets the basic requirements that Hollywood has laid down for anyone tackling the role: rakishness, a youthful quality, good hair. Other actors who’ve played Kennedy include Greg Kinnear, William Devane, Patrick Dempsey, and Martin Sheen (who’s also played Robert F. Kennedy).

Cliff Robertson played Kennedy in “PT 109” (1963), about the future president’s heroism after his boat was sunk during World War II. Kennedy stated a casting preference for Warren Beatty. Clearly, he had an acute sense of his own persona, Beatty’s romantic history, or both.

Even when he’s not onscreen, Kennedy can exert a powerful hold on a movie, from “Executive Action,” the 1973 paranoid thriller which posits a conspiracy behind the assassination, to “In the Line of Fire” (1993), where Secret Service agent Clint Eastwood (who was on duty in Dallas on Nov. 22, 1963) remains haunted 30 years later by his inability to save the president. Above all, there’s Oliver Stone’s “JFK” (1991), in which the title character haunts a movie in which he appears for only the briefest, blurriest instant. (Stone’s film is part of a commemorative DVD box set “Ultimate Collector’s Edition” detailed on Page N9.)

ASSOCIATED PRESS/FILE 1963

Cliff Robertson as JFK in “PT 109.” ”

The clearest testament to JFK’s star power comes courtesy of the man himself, in Robert Drew’s two cinema-vérité documentaries. “Primary” chronicles the 1960 Wisconsin Democratic primary, and “Crisis: Behind a Presidential Commitment” (1963) looks at federal intervention in desegregating the University of Alabama.

Cinéma vérité required the invention of cameras and audio recorders light enough for portability. For it to achieve its full potential, it required something more: protagonists utterly irresistible to the camera, utterly unself-conscious in front of the camera, and at the same time utterly self-aware. Bob Dylan, in D. A. Pennebaker’s “Don’t Look Back” (1967) would be a good example. JFK in these two documentaries is another. He commands the screen as well as he does not because of the office he holds or the centrality the camera grants him. He commands it because of who he is. That’s what stars do, the ones who live in Washington no less than the ones who live in Hollywood. Except that only one has lived in Washington, and he died 50 years ago this month.

BostonGlobe.com complimentary digital access has been provided to you, without a subscription, for free starting today and ending in 14 days. After the free trial period, your free BostonGlobe.com digital access will stop immediately unless you sign up for BostonGlobe.com digital subscription. Current print and digital subscribers are not eligible for the free trial.

Thanks & Welcome to Globe.com

You now have unlimited access for the next two weeks.

BostonGlobe.com complimentary digital access has been provided to you, without a subscription, for free starting today and ending in 14 days. After the free trial period, your free BostonGlobe.com digital access will stop immediately unless you sign up for BostonGlobe.com digital subscription. Current print and digital subscribers are not eligible for the free trial.